I'm no expert, but I believe it would be best to place it inside it's dustbag first. I wouldn't want any tissue or plastic to come in direct contact with it. I would also make sure it was stuffed with paper/tissue so that the leather would not come into contact with itself (ie. folded). After it is in it's dustbag I think just good ol' common sense packaging depending on the size/shape of bag so it is not folded in anyway. (If the bag folded in anyway it could potentially stick to itself, ouch!)
Hmmm, thats a really good question. I think it depends on what type of RM it is....If it's a Nikki, I think it would be fine it was stuffed, with the handle tucked inside the bag with the dustbag on. I don't think any of the patent would be touching as long as its shipped completely flat, not being squished.
If its an MAM or MAB, it might be difficult because of the handles. I think I would probably stuff the bag to the max, and then wrap the handles with alot of tissue paper.
I've never had to ship a patent bag, so I'm really any help...just a few suggestions...HTH.
I'm sure the other minkettes will have GREAT ideas...